Planing Plastic?


Did you know that you can plane plastic? Me neither. I used my old Stanley #4. Its sweetheart era blade was razor sharp, though I’m not sure it needed to be. The “shavings” are UHMW (Ultra High Molecular Weight) polyethylene. I also mic’ed these (never measured shaving with a micrometer before either). They were exactly .001″. The plane left a beautiful surface on the plastic. Smooth as glass.

Guess what else? You can cut this stuff with a chisel too. Live and learn.

I’m using UHMW for the drawer runners in the little toolchest I’m building.  I originally had some maple for this, but I wanted to try using some new materials just to see if I could do it.  After a great deal of searching I finally found exactly what I wanted – 5′ strips of this stuff already dimensioned to 1/2″ x 1/4″.  When it arrived, it was exactly 1/4″ thick material, but the 1/2″ dimension was rough sawn.  Of the two, I would have rather had the 1/4″ rough.  The drawer sides are grooved to accept 1/2″ runners. Honestly, I panicked a little at first.  How am I going to cut this stuff?  Can I sand it?  Scrape it?  Turns out it planed beautifully.

One trick:  Once I cut the strips to length, they were twisted or bent slightly.  You can hand form this stuff.  I got out the piece of Corian I used to use for scary sharpening and used it like a surface plate to make sure it was pretty straight.  This helped with the planing too.  This stuff has no real stiffness of its own.  You need a good flat surface to work on.  That’s not my bench!

9 thoughts on “Planing Plastic?

  1. Sternberg

    I plane the edge on plexiglass every now and again. It is a good test of sharpness. It does leave a very nice edge after a rough cut on the table saw. You can make very nice runners for jigs that way, and good router templates.

  2. mzierten

    UHMW polyethelyene is similar to nylon, both are kinda soft, and tend to deform easily. I once made a part in a machine shop with nylon and the deflection made it difficult to hold tolerances with. Delrin is a better choice if you need dimensional stability and a low coefficient of friction.

  3. Jonas Jensen

    Do you know if bone or ivory were ever used as drawer runners?
    I suspect that normal bone from an ox would do. Elephants who will give away their teeth tend to be a ittle harder to find.

    And a last thing; please Adam, can we have a drawing for your small toolchest?
    Brgds
    Jonas

  4. zdillingerzdillinger

    You can also plane aluminum, although it is tough on the plane iron, body too if you use a wood plane (don’t use a wood plane, save them for the real stuff).

  5. Bill Lattanzio

    I used UHMW for the runners on my panel sled. I was skeptical about the plastic machining like wood, as the manufacturer states. But I had no problems putting a minor back bevel on the plastic using a block plane. It is a bit too flexible for my taste but it worked well. My one minor issue with it was that when I installed it with screws it bulged a bit, even after a pilot hole and counter sink. Even still, it worked as advertised.

  6. Edward in Vancouver

    Yup, been doing that for about 10 years now, albeit with nylon cutting boards. I “used to” make some extra change resurfacing nylon cutting boards from my employers-by running them through my Dad’s thickness.

    FWIW, Matfer, a fancy French kitchen equipment Co, that supplies professionals has a “cutting board resurfacer” looking remarkably like a LV Bu smooother-but with disposable blades, and oriental sushi chefs tend to iron their nylon cutting boards smooth with a regular clothes iron.

    1. Adam CherubiniAdam Cherubini Post author

      Plowed! Kinda funny too. Using a 150 yr old tool to cut modern materials! That wasn’t as easy as surface planing it. I had to make a ….jig… to hold the plastic. In retrospect, I should have just cut the 1/8 or 3/16″ dado in the case side with a chisel. Hate to make jigs, let alone for 2 parts!

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